Amyotrophic lateral sclerosis (ALS or Lou Gehrig's disease) is a fatal neurodegenerative disease with a typical lifespan of 3 - 5 years after diagnosis. The initial symptoms can be similar to many other neurologic disorders and often begin with limb weakness, muscle fasciculations, or increasing difficulties in speech or breathing. No definitive diagnostic tests currently exist for ALS, and clinical diagnosis typically takes 12 months from symptom onset and relies on ruling out other potential causes of the clinical symptoms. Earlier diagnosis will permit more rapid initiation of treatment with newer drug therapies in development, or equally important provide a means to rapidly rule out ALS as a cause of the symptoms. Iron Horse Diagnostics, Inc. was created to finalize the development of diagnostic and prognostic indicators of ALS and market these assays as laboratory developed tests (LDTs) in a Clinical Laboratory Improvement Amendments (CLIA) certified lab. We have produced a series of peer-reviewed publications convincingly demonstrating that significant levels of pNfH and complement c3 can be detected in the blood and CSF of ALS patients, and that the levels detected by our assays provide diagnostic utility for ALS. We propose a series of tasks to optimize and validate our assays in a CLIA certified laboratory, the last remaining steps before commercialization. This is a FastTrack application because the remaining steps before Phase III are well defined with highly definable go/no-go gates. During Phase I of the proposed work, we will finalize and optimize assays as diagnostic indicators of ALS by testing samples for indicative proteins and translating the assay technology onto a new platform. Phase II will expand on this by conducting a multi-center prospective clinical research study and qualifying the assays using patient samples in a CLIA-certified lab to determine the overall accuracy of the ALS diagnostic. The goal of this proposal is to generate a sensitive and validated LDT (Lab Developed Test) for these biomarkers useful for clinically diagnosing ALS in a CLIA certified lab. A certified LDT will be marketed to clinicians as a service.